1. CONTENTS (1) RESEARCH OBJECTIVES There are many problems with real estate transactions. Upon termination of a lease, a tenant must restore the original state of the rented properties and the landlord can demand it. However, if the cost of restoration exceeds its economic value, many people say that the landlords abuse their rights. But, the economic cost is not an absolute standard of judgment. In this study, we will review this. (2) RESEARCH METHOD At first, we will collect and analyze past cases in connection with the restoration of the lease materials or incidental materials and also will refer to the related laws and papers. Then, we will observe the case submitted to a court in August 2010. (3) RESEARCH FINDINGS Analysis showed that the cost of restoration could exceed its market value. But, there are many factors must be rewarded for a tenant. 2. RESULTS A tenant is a week person economically. When a fire broke out in the building possessed by a landlord, he will not be rewarded enough because the landlord never restores tenant's assets perfectly with an excuse. Economic cost can be a unique and clear standard of restoration benefit.